Effect of Coulomb interactions on the optical properties of doped graphene

TL;DR

This paper presents a phenomenological model incorporating Coulomb interactions and marginal Fermi liquid behavior to explain unusual optical conductivity features in doped graphene, also predicting anomalous Raman signals.

Contribution

It introduces a new phenomenological approach considering Coulomb interactions and marginal Fermi liquid effects to explain optical properties of doped graphene.

Findings

Explains the strong background in optical conductivity between intra and interband transitions.

Predicts anomalous electronic Raman signals in doped graphene.

Provides qualitative agreement with experimental observations.

Abstract

Recent optical conductivity experiments of doped graphene in the infrared regime reveal a strong background in the energy region between the intra and interband transitions difficult to explain within conventional pictures. We propose a phenomenological model taking into account the marginal Fermi liquid nature of the quasiparticles in graphene near the neutrality point that can explain qualitatively the observed features. We also study the electronic Raman signal and suggest that it will also be anomalous.